Can anyone help? My customer has a very old system and part has been removed. He is replacing a steam boiler and is figuring the capacity. The coils are much like fin tube, have duct off the back, can't tell you if their is a blower or just outside air. There two 12"dx27wx34"h. Model 331616 10-design 175-size. They are no longer in business. Anyone out there have any ideas?